She may look familiar because of a recently released Nike ad on Unlimited Youth, which trains the spotlight on an elderly nun still living an active lifestyle.

In real life, Sister Madonna Buder holds the record for being the oldest person to complete an Ironman challenge at the age of 82 way back in 2014. She completed the Iron Man challenge by swimming 2.4 miles, biking 112 miles and running a 26.2-kilometre marathon in a span of 16 hours and 32 minutes.

She has become an inspiration for active aging, especially among netizens who know her story.

But the Iron Nun shrugs off the compliments and instead uses her lifestyle as her ministry. In a recent interview with Growing Bolder, Sister Buder encouraged everyone to discover their gifts and fulfill their purpose to serve God.

"To change the world that you are in, give to the world what you have and serve the world with what or who you are. If that doesn't say what we're here for I don't know what does," she said.

"It means digging deep to learn who you are and what you can do. We are all given different talents and different skills and we can't use them until we discover them. So once you have discovered it, you are obligated to use those talents and skills for the greater good of your creator," she explained.

For herself, she only started running at the age of 48 after her parish priest urged her to do so to keep her healthy in mind, body and soul. She has been doing it ever since.

Sister Buder admitted that because of her age, she also suffers from training injuries or sometimes, while running the race, she would encounter some unforeseen struggles.

In cases like these, she leaves her fate to God and talks to Him.

"All these decisions I'm having to take is a step out in faith. I have to say, 'Lord, please protect me.' Then it's ready or not, here I go," she said.